1. Field of the Invention
The present invention relates to a reception apparatus, a reception method, and a computer program, and more specifically, to a reception apparatus that receives data by multicast delivery, a reception method, and a computer program.
2. Description of the Related Art
Along with recent advances in network technology, programs (contents) have been delivered through networks. Providers that deliver programs convert the programs into IP (Internet Protocol) packets, and then deliver the programs from servers by multicast delivery in which the same signal is delivered to a plurality of recipients. Protocols generally used to receive programs by the multicast delivery include IGMP (Internet Group Management Protocol) for IPv4 network environments and MLD (Multicast Listener Discovery) for IPv6 network environments.
When a program by the multicast delivery is received using IGMP (or MLD), a reception apparatus transmits a signal that is called Join message when receiving a stream of a content. By transmitting the Join message, the reception apparatus can participate in a multicast group and view a content corresponding to the multicast group. To stop viewing the content, a signal that is called Leave message is transmitted. By transmitting the Leave message, the reception apparatus can leave the multicast group and stop viewing the content.
In the multicast delivery of contents through networks, since the transmission processing of a Join message and a Leave message as described above becomes necessary for switching contents, that is, switching channels, viewed in the reception apparatus, there arises a problem that a waiting time required for the channel switching is longer than for delivery by airwaves. Therefore, it is necessary to realize high-speed channel switching in the multicast delivery of contents through network.
Japanese Patent Application Laid-open No. 2008-022393 (hereinafter, referred to as Patent Document 1) discloses a method in which a home gateway device receives a stream obtained by multiplexing data of a plurality of contents, and when receiving information of a channel corresponding to a desired content from a receiving terminal, separates data of a content corresponding to the appropriate channel from the multiplexed stream to supply it to the receiving terminal.